Our overall goal is to understand the mechanisms in the behavior of a relatively simple organism by genetic dissection. This is done by producing lesions with mutagenesis and analyzing the resultant effects on behavior, electrophysiology, ultrastructure, and the biochemistry of the system. The organism of choice is Paramecium tetraurelia. Using locomotion as the indicator of the state of the excitable membrane, mutants with defective ion "channels" or "gates" have been isolated and analyzed. We intend to continue this interdisciplinary research. Specifically, we propose to study the patterns of ciliary membrane proteins by electrophoreses of purified ciliary membrane vesicles from wild type and mutants; to examine mutants or variants isolated in the K ion-enrichment procedures; to examine the orientation of the central pair in sections to correlate beat phases with orientation; to search for phospholipid changes in the mutants; and to study the effects on behavior after iontophoretic injections of ions and drugs.